MOMBE selective infill growth of InP/GaInAs for quantum dot formation

Quantum dots based on InP/GaInAs quantum wells were realised using epitaxia l infill regrowth into a hole array formed in InP by means of e-beam lithog raphy and reactive ion etching. Metal organic molecular beam epitaxy has be en applied for selective infill growth. The growth procedure has been elabo rated such that the vertical growth rate in predefined holes agrees with co herent growth and edge effects are minimised. Quantum dots formed in holes with a diameter ranging from 60 nm down to 30 nm in combination with a peri odicity of 100 nm were studied. The achievement of quantum dots was evidenc ed by a blue shift of light emission with decreasing the geometrical quantu m dot diameter, in qualitative agreement with calculations. Quantitative di screpancies were found because the effective lateral diameter of the quantu m dots proved to be smaller than the geometrical value of the etched holes, caused by the lateral growth of the lower InP barrier. (C) 2000 Elsevier S cience B.V. All rights reserved.